Carburetor



June 41 192s. 1,586,601

P. c. BOOTY GARBURTR Filed nec. 2o. 1920 z sheets-sheet 1 June 1 1926.

P. C. BOOTY CARBURETOR Filed Dec. 20. 1920 2 Sheets-Sheet 2 Ohms ' of Fig. 1.

Figure 3 is a plan section on the lines 3 -3 of Fig. 1.

Patented June 1, 1926.

" UNITED STATE rHILII droom, or CHICAGO, ILLINOIS.

CARBIIRETOR.

Application filed December 2o, 1920.l sensi No. 432,155.

, My invention relates to a carbureting device andy particularly to a carburetor `ofthe constant vacuum type for internal combustion engines. v

One object of the invention is to provide a carburetor 'ofiinproved construction for which' will not be affected or damaged by theback` firing` or by the presence of particles of dust.

It is a further object of this invention to provide a carburetor of this typeA of such simplified construction that allowable tolerance or departures from exactness in manufacture or machining'. may be `increased without impairing the efficiency of the device, whereby the cost of manufacture may be decreased and the rate of output increased. 4

A still yfurther object isto provide a carburetor of this type having a short passage of substantially uniform Vcross section for conducting mixture ,f l into the manifold, whereby condensation of the fuel in lthe carburetor is avoided. l

The invention consists in the novel constructions,` .combinations and devicesto be hereinafter described and claiined,vr for carrying out the abovest-ated objects and such other objects as will appear from the fol-` lowing description.

In the drawings I have illustrated ya preferred embodiment of the invention, where- 1na Figure 1 is a central sectional elevation through the carburetor and float chamber.

Figure 2 is a plany section on the line 2 2 Figure 4 is a perspective'of the air valve or double piston, and

Figure 5 is an enlarged, longitudinal section of'the lower portion of thel fuel` valve.

Likeeheracters of reference desi *nate like parrain the several figures cf,Y the, C nieuwe. Th `cfirbifittor lierei disloed eiii-bedies erteih improvements- 'everr the prier funn of device shown in the application ofPhilip 6Q Booty Serial No. 281,033 vfiled March 9. "Referring to the drawings, 5 designates a tubular carburetor casing closed at its u Vper end by a cap A(i land pro-vided with an air uintake opening Z at its lower end and a de-v livery duct 8 leading from the side of; the casingat an intermediate point. The casing 5 comprises an upper cylindricalportion 9 and a lower cylindrical, portion 10, which 9 and 10 is a portion 11 of. somewhat larger internal diameter than that of the portions PATENT oi-Ficef .are in enact alignment and are preferably of the saine` diameter. Between the portions 9 andV 10, suchiiitermediate portion having a delivery duct 8 vformed therewith and leadlng vfrom Vthe side thereof. The portions 9 and 10 are adapted to be drilled and reained to proper y bore by tools inserted through the opening covered by the cap 6. By offsetting the wall of the struc-ture at the intermediate portion 1-1, as indicated at l2, for

example, the' reameris permitted to extend in true axial alignment for operation on they cylinder portion 10, since there is thus ynoy necessity for removing any metalk kat the point oppositethc open inner end of the duct 8.

- rThe casingat` the end of the lower cylindrical portion 1 0 is also odset as kindicated at 13 to provide a clearance space so that the boringand reaming tools may be permitted to pass clear th-ioughthe portion 10 before they are'stopped, the necessity for accurate gauging being thus avoided. This `serves also to lprovide a larger a-ii` inlet open-r ingto the lower portion of the part 10. The delivery Vduc-t is kprovided with the usual throttle valve 14 and is flanged at its eX- tremity, shown at 15, to permit attachment to thel usual intake manifold.V In the center of the casing is a fuel nozzle 16'teiminating in a fuel orificevlS and preferablyv detachably secured by screw threads to a fuel supply duct 19. The fuelisupply duct-19 is preferably cast integral with the casinglO and supplies fuel from the yfioat chamber 20, also preferably cast integral with the casing 10. Plugs 21 and 22 close openings in the fuel. assage made therein for convenience in filling the fuel duct. g

The float chamber .comprises thenual lie-at 23 which carries the `needle, valve 2e leosely seemed einem The needle'y valve projects downwardly through the inlet tube which is slotted at 26 to permit the entrance of fuel and which is screwed at its lower end into a fitting 27, itself screwed to the bottom of the float chamber 20. The inlet tube 25 is provided with a seat 28 for the needle valve. A hollow member 29 having a threaded opening 30 for the connection of the fuel pipe 31 is held against the fitting 27 by a cap nut 82. The fitting 27 is formed with a central duct 33 and transverse openings 34 and surrounded by a filter screen 35.

Disposed within the casing 10 and slidable along the nozzle 16 is a cone 36 having its larger end toward the air inlet. The cone is adapted to be adjusted vertically within the casing by a link 37 pivotally connected to a rocker arm 38. rl`he rocker arm is secured to a rock shaft 39 which is supported by bearings provided by the wall of the casing below the lowercylinder portion 10, one end of the shaft being provided with another rocker arm 40. The latter arm is connected to a rod 41 which leads by suitable connections (not shown) to a convenient position on the dash or elsewhere, so that an adjustment of the core may be easily etfected. The link 37 is connected to the cone by a ball and socket joint comprising a plug 42 screwed into the cone and having a socket therein within which the ball 43 on the link is adapted to seat. The casing 10 is provided with a suitable housing 44 for enclosing the link 37, arm 38 and a portion of the rock shaft 39.

Slidable within the casing is an air valve 45 comprising at its lower end an annular piston 46 surrounding the cone and serving to close the space between the cone and the wall of the casing, a piston 47 at its upper rnd and an intermediate connecting struc ture 48. The connecting structure 48 is preferably cut away so as to leave only a plurality of connecting strips 49 for rigidlyuniting the pistons 46 and 47. The cage comprising the piston 47, the valve 46, and the arms or strips 49, is held from rotating by an inwardly extending pin 51 carried by the wall of the casing and engaging a vertical slot in one of the arms 49. The arms 49 are thus prevented from turning into position to obstruct the. outlet port. The annular piston 46 is preferably provided with a plurality of peripheral grooves 52 for the purpose of preventing the leakage of any substantial amount of air around the piston. The upper piston 47 may also be similarly grooved, although the matter of leakage past this piston is not important, for reasons hereinafter pointed out. The cone 36 is preferably provided with a plurality of projeetions 36 which are adapted to engage the lower face of piston 46 and by means of which the air valve may be bodily raised by raising the cone` This construction is advantageous in starting, as will be hereinafter pointed out.

Secured to the piston 47 is a fuel valve ,if a diameter corresponding to the fuel orifice 18 and provided with a plurality of grooves 54 of uniform width and uniformly increasing in depth toward the lower end of t-he valve. The valve 53 is suspended from the piston 47 by means of a transverse pin 55 through the end thereof so as to permit the same to hang freely lwithin the nozzle 16. A removable screw plug 56 retains vthe valve in place and also permits its removal but does not actually engage the end thereof, being adapted thus not to interfere with the freedom of movement of the valve. The piston 47 is provided with av valve controlled passage 57 for purposes hereinafter pointed out. A pointed valve 5S having a groove 59 therein, communicating with the passage 57, is adapted to control the effective size of this passage.

Operation: The depression created in the carburetor casing by the suction of the motor causes a lifting of the air valve 46 with respect Vto the cone 36 and a corresponding lii't-ing of the fuel valve until a balance between thc pressure on the lower face of the annular aiston 46 and the weight of the air and fuel valve is arrived at. The fuel valve is graduated so as to increase the size of the fuel Youtlet comprising the several grooves 54 substantially in proportion to the lift of said valve in the fuel nozzle. The contour of the cone 36 is such also that the effective size of the opening between the ring 46 and the cone 86 increases substantially in proportion to the lift of said ring or valve 46, Thus the ratio between the size of the air opening and the size of the fucl opening' rcniains constant as the valves are lifted. lt is thus apparent that as the throttle 14 is opened so as to cause the valves to move higher and higher, due to the increased depression in the casing, a correspondingly increased amount of fuel and air is forced through the casing, such fuel and air being always of uniform richness.

XVhen it is desired to :feed a richer mixture to the cylinders, or when for anyr reason it becomes necessary to increase the effective size of the fuel opening with respect to that of the air opening in order to get the desired richness of the mixture, this can be effected by a vertical adjustment of the cone 36. When the cone B6 is moved upwardly, with the engine at rest, the valve 46 will, of course. be moved upwardly with the cone, serving to move the pin valve 53 upwardly within the nozzle 16. This adjustment serves to open the valve 58 slightly but does not affect the valve 46 which still rests on the projections S6. iWhen the engine is started thereafter, the valve 46 is raised by Lil l liver a blow to the projections 36 and thence to the adjusting levers 38 and 40.

the suction the same as before with respect but this is merely for ease of explanation.

The adjustment can be made and ordinarily would be made with the enginev ruiming. 'l

The upper piston 4:7 is provided so that the responsivenessof the piston 46 to variations in thesuction of the engine may be con-y trolled. lThe piston 47 is'not otherwise essential to the operation previously described.

AIt desired, the piston 4T may serve merely as a guide and means of attachment :tor the fuel valve, suitable openings being made through the piston to permit the free move ment thereof in the casing. By providing` a controlledpassage through the piston, theY result above noted is accompli-shed. Ey screwing down the valve 58 the elfective size ot' the passagel through the piston is de-y creased and the lag yof the air valve kbehind the variation in suction is increased. If the air passage through the piston is increased, then the air valve is more responsive to variations in suction of the motor. The retardation ot' the responsiveness of the air valve with respect to variations in suction is desirable because the fuel lis more viscous than air and the owthereof does'not respond so readily to variations in suction as that of the air. Inasmuch as the piston 41:7 is to act merely to retard movement or the valves, a close lit of such piston lin the casing is not essential. In any event, inadjusting the valve 58, the leakage past the piston will always be taken into consideration.

By the provision of the piston I7 with its bottom pressure face opposed to the top pressure race of the valve ring 4.6, the pressure of back-hringiin the casing does not drive the air-valve downwardly so as to c.e-

The downward pressure of theback-lire is more lthan balanced by the upward pressure on the lower 'l'ace of the piston 47, so that in fact the back iirevery slightlylifts the air valve. i

The connection of the delivery duct to the side of thecarburetorcasing below the upper casing portion also prevents the presence oi dust particles from causing wear or" or otherwise interfering with the operation of the upper piston .4-1. y v n drawn into the manilold and are afforded no Vand Vmeans for preventino' `Dust particles are opportunity r'or lodging in the upperV end of the carburetor casing.

In my improved construction, the operation of the piston l? is entirely independent of any air leaking pastthe ring piston 4G. The nicety of tit between-the ring 4by and the casing portion l() is accordingly dependent only onV the'` necessities with respect toA the use of the valve for controlling the aiiionntofair passing to the engine. I have found that the tolerance in this respect is coniparativeiy large .withoutdanger kot" interiierino' seriously ywith elii'ective operation.

By providing a casing in which the cylin-` drical portions kareoir the same diameter, the construction and machining of thecasing is not only L'much simpliiiedbut a uniyiorm passage is provided for the mixture so that no opportunity isaiiiorded for condensation o'ltlie iiuel within the casing resulting iiroin a` retardation 'of this velocity through a `passage of increased cross section.

I claim: n Y s l. In a carburetor, the combination of a casing, anupwardly movable member adaptn ed partially to close the casing at its lower end portion, a valve supported by said meniber and effectivelyy closing the remainder ot' the lower end of the casing, means for moving said member upwardly and for holding it in adjusted elevated position, said valve opening upwardly away from said member, the pressure o backncire in the casing ,trom causingthe valveto slam downwardly against said movably supported member.

' 2. In a carburetor, the combination of a casing, an upwardly movable member adapted partially to close the casing at its lower end portion, a valvesupportedby said member and' effectively closing theremainder of the lower end olitlie casing, means for moving saidunember upwardly and lfor holding it in elevated position, said valve opening upwardlyaway fronisaid member so that the pressure of backfire on the upper face of the valve tends to move the valve downwardly against said adjustablysupported member, and means having a downwardly-disposed pressure Jface movable with the valve adapted by a preponderance of pressure or' back-lire thereon as compared 

